Cooperative Use of IMD and GPT in a 3-Phase Ungrounded Distribution System Linked to a Transformerless Photovoltaic Power Generation Facility

Distributed generations, using solar photovoltaic (PV) generation systems, are generally connected to ungrounded distribution systems ensure operational continuity and avoid electro-chemical corrosions. The power system possesses an advantage of continuous operation regardless primary fault occurrence due a small current. Conversely, subsequent secondary can induce large current representing that other electrical grounding types, resulting in inevitable shutdowns. As preventative methods, both insulation status monitoring failure detection have become high importance. This paper presents method enabling the cooperative use IMD (Insulation Monitoring Device) GPT (Ground Potential Transformer) with transformerless inverter. Moreover, factors leading errors during monitoring, CLR (Current Limit Resistor) burnout GPT, malfunctions related protection devices presented. Furthermore, for selecting inductor capacitor consideration operating characteristics is discussed. proposed enables accurate measurement resistance IMD, while concurrently reducing constitutively induced zero-sequence voltage prevent burnouts devices. Hence, anticipated contribute stable alternating (AC) Direct Current (DC) combined inverters.